Is COVID19 infection gender-biased to males due to their smoking status?
There are few theories which could explain the protective mechanism for women including hormonal balance, inherent low comorbidity status, and low tobacco smoking/ consumption, says Dr Hitesh R Singhavi
The World Health Organisation (WHO) declared COVID19 as pandemic on 11th January 2020, as it spread to almost all major countries in the world infecting 6.3million individuals and killing more than 350,000 human beings. Similarly, in India up till now we have 200,000 infected cases with mortality rate of 3.2%, even after strict governmental measures like Janta Curfew and social distancing norms.
Gender distribution of COVID19 infected cases has been skewed towards males throughout the world. COVID19-related death rate in males is almost 2 times that of females, as per the WHO. According to data reported by Public Health Dept., Government of Maharashtra, on 1st June 2020, 62% of all the infected individuals were males while their death share was even higher, at 64%.
Now in the wake of mitigating governmental measures and lifting of lockdown, there is danger of faster spread of infection, overwhelming our healthcare system. Therefore, we can avoid being caught off guard if we can identify high risk individuals who have higher chances of severe COVID19 infection. Those with comorbidities, and the elderly age groups are established poor prognostic factor. However, it’s also seen that male as a gender factor is also in a precarious position. Tobacco consuming males either in the form of cigarettes or smokeless tobacco fall in this category.
The Global Adult Tobacco Survey (GATS) is the survey conducted to monitor tobacco use assisted by WHO under the Framework Convention on Tobacco Control. According to GATS2 (2016), 42% of the entire populations of males consume tobacco in some form. Chronic use of Tobacco can cause Chronic Obstructive Pulmonary Disease (COPD). Globally, COPD (a form of lung disease) is the fifth most common cause of death. Major result of Tobacco-associated morbidity is seen in the lungs; SARS-Cov-2 drowns the Lungs in the inflammatory Cytokine Storm. Just imagine the amount of Lung destruction when the combination of tobacco associated COPD and SARS-Cov-2 would hit your Lungs. Coincidentally, these duos are found to be present more in Males.
Wait, are we trying to connect two random points with a thought or there is actually direct relation to it? To find this, we went into literature to find the missing link. We found a meta-analysis (study estimating pool of studies) analysing 206,000 infected cases, which state males to have double the risk of serious infection (ICU admission), in this study it was found that 50% of the Chinese males were smokers as compared to 2.1% females.
Another study published in Lancet 2020, Hua Cai demonstrated that differences in COVID-19 disease prevalence and severity are associated with gender, and smoking is related to higher expression of ACE2 (the receptor for severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2]). One study lead by Wuhan’s scientist Zhao, studying single-cell sequencing, found that expression of ACE2 was more predominant in Asian men, which might be the reason for the higher prevalence of COVID-19 in this subgroup of patients than in women.
There are few theories which could explain the protective mechanism for women including hormonal balance, inherent low comorbidity status, and low tobacco smoking/ consumption. Thus it is necessary not only to maintain social distancing from humans to prevent COVID-19 infection, but also to maintain safe distance from Tobacco to significantly reduce its death rate, especially amongst males!
Dr Hitesh R Singhavi is Consultant, Head & Neck Oncology with Fortis Hospital, Mulund.